On New Year's Eve, one of the busiest days of the year at Walt Disney World, three of the giant resort's four theme parks stayed open until 1 a.m. or later.

The fourth — Disney's Animal Kingdom — shut down at 8 p.m.

The contrasting holiday schedules underscore what has become a persistent problem for Animal Kingdom, the 15-year-old park that combines a handful of marquee rides and shows with a collection of more than 1,700 animals. Although the park draws plenty of people through its gates each morning — nearly 27,400 a day, on average — it doesn't keep them very long. Some fans dismiss it as a "half-day" park.

To fix that problem — and to better compete with Comcast Corp.'s rapidly growing Universal Orlando — Walt Disney Co. last week broke ground on an estimated $800 million renovation and expansion of Animal Kingdom. The goal of the multiyear project, whose centerpiece will be a lavishly themed new land based on the "Avatar" film franchise, is to transform Animal Kingdom into a full-day destination that can command crowds' attention well into the evening.

Senior Disney executives are enthusiastically talking up the project, likening it to their $1.1 billion, five-year rebuilding of Disney California Adventure in Anaheim, Calif., which has propelled the entire Disneyland Resort to record attendance and profit. The Animal Kingdom work is a personal priority of Tom Staggs, chairman of Disney's global theme-park division, who helped negotiate Disney's "Avatar" licensing deal with filmmaker James Cameron and 20th Century Fox.

Disney would not make any executives available to discuss the project, which was first announced in 2011 and won't be complete until 2017. But in a prepared statement, Staggs called it an "opportunity to take a park that already is home to some of our guests' favorite attractions and make it even better.

"The expansion enables us to bring the popular stories of 'Avatar' to life and introduce evening entertainment that will make the park a true full-day, must-see experience that further rounds out our overall Walt Disney World experience," Staggs added.

Disney says the parallels with California Adventure aren't perfect. Although company leaders publicly acknowledged that the original California Adventure fell far short of projections, they say they have been pleased with Animal Kingdom's performance.

Disney says Animal Kingdom is home to three of Disney World's 10 highest-rated attractions: Expedition Everest, Kilimanjaro Safaris and Festival of the Lion King. According to the Themed Entertainment Association, Animal Kingdom drew 10 million visitors in 2012. That was about 90,000 more than Disney's Hollywood Studios and 2 million more than Universal's Harry Potter-powered Islands of Adventure.

Still, the park's struggle to keep guests for a full day has become a hard-to-ignore flaw because it has exacerbated overcrowding problems elsewhere at Disney World. Many of the visitors checking out of Animal Kingdom in midafternoon head for the Magic Kingdom, which is bursting with more than 17 million annual visitors, or the Downtown Disney retail area, which struggles with parking shortages in the evenings.

"What's ultimately driving this is that they're trying to increase the capacity of Walt Disney World," said Robert Niles, publisher of ThemeParkInsider.com. "With Animal Kingdom, they've had this huge, expensive asset sitting there that they aren't utilizing to the same extent as the other parks."

Crowding and long lines are one of the most commonly cited deterrents for travelers thinking about Disney World vacations. Many of Disney's most recent Orlando expansions have been aimed at creating more breathing room and better spreading people across its property.

For example, the not-yet-completed $425 million Fantasyland expansion was designed to relieve pressure in the Magic Kingdom, which was already the busiest park in the world.

And one goal of the $1 billion MyMagic+ technology project, which remains in testing, is to get as many as 90 percent of Disney World visitors reserving some of their rides in advance. Only a bit more than 50 percent of the resort's visitors use Disney World's current Fastpass system, and those that do typically obtain Fastpasses for only two rides per day.

Disney has so far disclosed only a few details about its Animal Kingdom work. Additions will include an evening show combining live music, floating lanterns, water screens and swirling animal imagery, along with a revamped, nighttime version of its Kilimanjaro Safaris ride. The "Avatar" land, which will be the final phase and will open sometime in 2017, will feature floating mountains, lush jungle scenery and a ride meant to evoke riding a "banshee," a birdlike predator featured in the film.